Challenge Library
Coding Challenges
5,893 curated questions across every arena — browse by topic, then jump into a live 3-minute battle to put them to the test.
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112 challenges matching your filters
Clear topic filter- Code AnalysisHard
Trace: Signed Left Shift
canalysishard - Code AnalysisHard
Trace: char Sign
canalysishard - Code AnalysisHard
Trace: Struct Size
canalysishard - Code AnalysisHard
Trace: Alignof
canalysishard - Code AnalysisHard
Trace: Array Decay
canalysishard - Code AnalysisHard
Trace: Bit Mask
canalysishard - Code AnalysisHard
Trace: Bitwise NOT
canalysishard - Code AnalysisHard
Trace: Popcount Trick
canalysishard - Code AnalysisHard
Trace: Sign Bit Shift
canalysishard - Code AnalysisHard
Trace: XOR Swap
canalysishard - Code AnalysisHard
Trace: Comma Operator
canalysishard - Code AnalysisHard
Trace: Stringify Macro
canalysishard - Code AnalysisHard
Trace: Division by Zero
canalysishard - Code AnalysisHard
Trace: Enum Values
canalysishard - Code AnalysisHard
Trace: Extern Concept
canalysishard - Code AnalysisHard
Trace: Function Pointer
canalysishard - Code AnalysisHard
Trace: Variable Shadow
canalysishard - Code AnalysisHard
Trace: Ifdef
canalysishard - Code AnalysisHard
Trace: Macro Pitfall
canalysishard - Code AnalysisHard
Trace: Pointer Arithmetic
canalysishard - Code AnalysisHard
Trace: Pointer Difference
canalysishard - Code AnalysisHard
Trace: Double Pointer
canalysishard - Code AnalysisHard
Trace: Recursive Factorial
canalysishard - Code AnalysisHard
Trace: Recursive GCD
canalysishard - Code AnalysisHard
Trace: Negative Shift
canalysishard - Code AnalysisHard
Trace: Signed Overflow
canalysishard - Code AnalysisHard
Trace: Static Variable
canalysishard - Code AnalysisHard
Trace: Strcmp Result
canalysishard - Code AnalysisHard
Trace: String Literal Size
canalysishard - Code AnalysisHard
Trace: Struct Padding
canalysishard - Code AnalysisHard
Trace: Typedef
canalysishard - Code AnalysisHard
Trace: Union Access
canalysishard - Code AnalysisHard
Trace: Void Pointer
canalysishard - Multiple ChoiceHard
restrict
cmcqhard - Multiple ChoiceHard
Strict Aliasing
cmcqhard - Multiple ChoiceHard
Unsequenced Modification
cmcqhard - Multiple ChoiceHard
Flexible Array Member
chard - Multiple ChoiceHard
Designated Initializer
chard - Multiple ChoiceHard
Compound Literal
chard - Multiple ChoiceHard
_Generic
chard - Multiple ChoiceHard
_Atomic
chard - Multiple ChoiceHard
_Alignas
chard - Multiple ChoiceHard
_Static_assert
chard - Multiple ChoiceHard
Opaque Pointer
chard - Multiple ChoiceHard
VLA
chard - Multiple ChoiceHard
alloca
chard - Multiple ChoiceHard
Memory Ordering
chard - Multiple ChoiceHard
Duff's Device
chard - Multiple ChoiceHard
X-Macro
chard - Multiple ChoiceHard
Obfuscated C
chard - Multiple ChoiceHard
Strict Aliasing
chard - Multiple ChoiceHard
TLS
chard - Multiple ChoiceHard
CTAD
chard - Multiple ChoiceHard
Nested Function
chard - Multiple ChoiceHard
__attribute__
chard - Multiple ChoiceHard
Integer Promotion
chard - Multiple ChoiceHard
Usual Arithmetic Conversion
chard - Multiple ChoiceHard
Trigraph
chard - Multiple ChoiceHard
Digraph
chard - Multiple ChoiceHard
Locale
chard
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